The integral mounting of a fuel pressure regulator valve on a fuel rail typically necessitates the inclusion of a sealing means between the valve and the rail so that fuel that is present in the rail does not leak from the rail via potential leak paths between the valve and the fuel rail socket that receives the valve. Typical sealing means comprises one or more O-ring seals, which are usually made of a fuel-resistant elastomer.
In one known design the O-rings may remain in the socket when the pressure regulator valve is removed. Therefore whenever service requires that the valve be removed from the fuel rail, the possibility exists that a negligent person may either loose the O-ring seals or improperly re-install them.
In another known design, the O-rings will remain on the valve when it is removed from the socket, but the design possesses a relatively expensive construction for the regulator valve housing and requires fuel pressure testing. The housing comprises three parts, namely a stamping and two screw machined parts which are assembled with the use of both brazing and crimping. The grooves that are required for the O-ring seals are in one of the screw machined parts and the brazed joint which joins the stamping and one of the screw machined parts and bounds the fuel chamber is outside the zone of sealing that is provided by the O-ring seals. Because of this construction, pressure testing of the brazed joint is essential to ensure that it does not leak.
The present invention relates to a new and unique construction for a fuel pressure regulator valve mounted integrally on a fuel rail whereby the O-ring seals will remain on the valve when the valve is removed from the fuel rail while the O-ring retention on the valve housing does not require the use of screw-machined parts to provide the grooves for the O-ring seals. Moreover, brazing of a stamping to a screw-machined part is avoided, and fuel pressure testing of such a joint is likewise avoided.
Accordingly, a fuel pressure regulator valve that embodies the inventive principles offers significant advantages over the known valves mentioned above. Additional advantages, along with further features, will be gathered from the ensuing description which is accompanied by drawings. The drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at the present time for carrying out the invention.